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Li C, Teng P, Peng Z, Sang P, Sun X, Cai J. Bis-Cyclic Guanidines as a Novel Class of Compounds Potent against Clostridium difficile. ChemMedChem 2018; 13:1414-1420. [PMID: 29768720 DOI: 10.1002/cmdc.201800240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/14/2018] [Indexed: 01/09/2023]
Abstract
Clostridium difficile infection (CDI) symptoms range from diarrhea to severe toxic megacolon and even death. Due to its rapid acquisition of resistance, C. difficile is listed as an urgent antibiotic-resistant threat, and has surpassed methicillin-resistant Staphylococcus aureus (MRSA) as the most common hospital-acquired infection in the USA. To combat this pathogen, a new structural class of pseudo-peptides that exhibit antimicrobial activities could play an important role. Herein we report a set of bis-cyclic guanidine compounds that show potent antibacterial activity against C. difficile with decent selectivity. Eight compounds showed high in vitro potency against C. difficile UK6 with MIC values of 1.0 μg mL-1 , and cytotoxic selectivity index (SI) values up to 37. Moreover, the most selective compound is also effective in the treatment of C. difficile-induced disease in a mouse model of CDI, and appears to be a very promising new candidate for the treatment of CDI.
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Affiliation(s)
- Chunhui Li
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Boulevard, Tampa, FL, 33612, USA.,Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Peng Teng
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL, 33620, USA
| | - Zhong Peng
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Boulevard, Tampa, FL, 33612, USA.,State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Peng Sang
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL, 33620, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Boulevard, Tampa, FL, 33612, USA
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL, 33620, USA
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Binyamin D, Nitzan O, Azrad M, Hamo Z, Koren O, Peretz A. In Vitro Activity of Tedizolid, Dalbavancin, and Ceftobiprole Against Clostridium difficile. Front Microbiol 2018; 9:1256. [PMID: 29942295 PMCID: PMC6004428 DOI: 10.3389/fmicb.2018.01256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 05/24/2018] [Indexed: 01/25/2023] Open
Abstract
Background:Clostridium difficile (C. difficile) is a major nosocomial pathogen that colonizes in the human gut. Recently, the U.S. FDA approved three new antimicrobial agents against gram-positive bacteria: Tedizolid, Dalbavancin, and Ceftobiprole. The efficacy of these antibiotics for treatment of C. difficile infection has not been thoroughly examined. The current study aimed to examine the in vitro activity of these antibiotics against C. difficile. In addition, to compare between Dalbavancin and Ceftobiprole to antibiotics from the same class: Vancomycin and Ceftriaxone, respectively. Methods: Eighty-four C. difficile isolates were tested for susceptibility to Tedizolid, Dalbavancin, Ceftobiprole, Vancomycin, and Ceftriaxone by Etest technique in order to determine the minimum inhibitory concentration (MIC). Results: Upon comparison of the novel antibiotic agents, Dalbavancin demonstrated the lowest MIC values and ceftobiprole the highest at MIC50 (0.016, 0.38, and 1.5 μg/mL, for Dalbavancin, Tedizolid, and Ceftobiprole, respectively) and MIC90 (0.03, 0.78, and 3.17 μg/mL, respectively). Dalbavancin demonstrated significantly lower MIC50 and MIC90 values compared to Vancomycin (0.016 vs. 0.38 and 0.03 vs. 3.5, respectively) (p < 0.001) and ceftobiprole had significantly lower MIC values compare to ceftriaxone (1.5 vs. 32 and 3.17 vs. 28.8, respectively) (p < 0.001). Conclusion: Dalbavancin and Tedizolid may play a role as potential therapeutic agents for treatment of C. difficile infection. Examination of antibiotic effect on the intestinal microbiome and clinical trials are needed for more accurate results.
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Affiliation(s)
- Dana Binyamin
- Clinical Microbiology Laboratory, Baruch Padeh Medical Center, Poriya, Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel.,The Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel
| | - Orna Nitzan
- The Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel.,Unit of Infectious Diseases, Baruch Padeh Medical Center, Poriya, Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel
| | - Maya Azrad
- Clinical Microbiology Laboratory, Baruch Padeh Medical Center, Poriya, Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel
| | - Zohar Hamo
- Clinical Microbiology Laboratory, Baruch Padeh Medical Center, Poriya, Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel.,The Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel
| | - Omry Koren
- The Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel
| | - Avi Peretz
- Clinical Microbiology Laboratory, Baruch Padeh Medical Center, Poriya, Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel.,The Azrieli Faculty of Medicine, Bar Ilan University, Galilee, Israel
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Ooijevaar R, van Beurden Y, Terveer E, Goorhuis A, Bauer M, Keller J, Mulder C, Kuijper E. Update of treatment algorithms for Clostridium difficile infection. Clin Microbiol Infect 2018; 24:452-462. [DOI: 10.1016/j.cmi.2017.12.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/29/2017] [Accepted: 12/31/2017] [Indexed: 12/11/2022]
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Abstract
PURPOSE OF REVIEW A resident microbial community [the female urinary microbiota (FUM)] exists within the female bladder of many adult women. Information about the FUM is likely to modify the diagnosis, prevention and treatment of adult women with urinary disorders. This review highlights key findings from recent literature relevant to adult, nonpregnant women. RECENT FINDINGS Similar to other human microbial communities, the FUM varies in its characteristics, including organism diversity and predominant organism identity. Recent literature reveals previously undetected organisms and community characteristics that appear associated with certain urinary symptoms, including urinary tract infection and urgency urinary incontinence. The role of individual organisms may range from beneficial to pathogenic and may vary on the basis of an individual's FUM characteristics. The simple dichotomy of 'infected' or 'sterile' no longer sufficiently captures the microbiological complexity of the female bladder. SUMMARY Deeper understanding of the FUM should yield better methods to restore the microbiota to a healthy state, providing symptom relief. Opportunities to modify the FUM without antibiotic use are exciting possibilities for future research; stand-alone antibiotic use may be reevaluated to improve treatment precision. Long-standing nomenclature for conditions such as asymptomatic bacteriuria and urinary tract infection will likely require modification.
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Abstract
This narrative review summarises the benefits, risks and appropriate use of acid-suppressing drugs (ASDs), proton pump inhibitors and histamine-2 receptor antagonists, advocating a rationale balanced and individualised approach aimed to minimise any serious adverse consequences. It focuses on current controversies on the potential of ASDs to contribute to infections-bacterial, parasitic, fungal, protozoan and viral, particularly in the elderly, comprehensively and critically discusses the growing body of observational literature linking ASD use to a variety of enteric, respiratory, skin and systemic infectious diseases and complications (Clostridium difficile diarrhoea, pneumonia, spontaneous bacterial peritonitis, septicaemia and other). The proposed pathogenic mechanisms of ASD-associated infections (related and unrelated to the inhibition of gastric acid secretion, alterations of the gut microbiome and immunity), and drug-drug interactions are also described. Both probiotics use and correcting vitamin D status may have a significant protective effect decreasing the incidence of ASD-associated infections, especially in the elderly. Despite the limitations of the existing data, the importance of individualised therapy and caution in long-term ASD use considering the balance of benefits and potential harms, factors that may predispose to and actions that may prevent/attenuate adverse effects is evident. A six-step practical algorithm for ASD therapy based on the best available evidence is presented.
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Inactivation of the dnaK gene in Clostridium difficile 630 Δerm yields a temperature-sensitive phenotype and increases biofilm-forming ability. Sci Rep 2017; 7:17522. [PMID: 29235503 PMCID: PMC5727486 DOI: 10.1038/s41598-017-17583-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/27/2017] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile infection is a growing problem in healthcare settings worldwide and results in a considerable socioeconomic impact. New hypervirulent strains and acquisition of antibiotic resistance exacerbates pathogenesis; however, the survival strategy of C. difficile in the challenging gut environment still remains incompletely understood. We previously reported that clinically relevant heat-stress (37-41 °C) resulted in a classical heat-stress response with up-regulation of cellular chaperones. We used ClosTron to construct an insertional mutation in the dnaK gene of C. difficile 630 Δerm. The dnaK mutant exhibited temperature sensitivity, grew more slowly than C. difficile 630 Δerm and was less thermotolerant. Furthermore, the mutant was non-motile, had 4-fold lower expression of the fliC gene and lacked flagella on the cell surface. Mutant cells were some 50% longer than parental strain cells, and at optimal growth temperatures, they exhibited a 4-fold increase in the expression of class I chaperone genes including GroEL and GroES. Increased chaperone expression, in addition to the non-flagellated phenotype of the mutant, may account for the increased biofilm formation observed. Overall, the phenotype resulting from dnaK disruption is more akin to that observed in Escherichia coli dnaK mutants, rather than those in the Gram-positive model organism Bacillus subtilis.
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Chow VCY, Kwong TNY, So EWM, Ho YII, Wong SH, Lai RWM, Chan RCY. Surveillance of antibiotic resistance among common Clostridium difficile ribotypes in Hong Kong. Sci Rep 2017; 7:17218. [PMID: 29222426 PMCID: PMC5722880 DOI: 10.1038/s41598-017-17523-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/27/2017] [Indexed: 12/15/2022] Open
Abstract
Incidence of Clostridium difficile infection (CDI) is rapidly increasing and it poses a major health burden globally. However, data regarding the epidemiology of CDI in Asia are limited. We aimed to characterize the antimicrobial susceptibility patterns of common ribotypes of toxigenic C. difficile in Hong Kong. Fifty-three PCR ribotypes were identified among 284 toxigenic C. difficile clinical isolates. The five most prevalent ribotypes were 002 (13%), 017 (12%), 014 (10%), 012 (9.2%), and 020 (9.5%). All tested C. difficile strains remained susceptible to metronidazole, vancomycin, meropenem and piperacillin/tazobactam, but highly resistant to cephalosporins. Of the fluoroquinolones, highest resistance to ciprofloxacin was observed (99%), followed by levofloxacin (43%) and moxifloxacin (23%). The two newly emerged PCR ribotypes, 017 and 002, demonstrated high levels of co-resistance towards clindamycin, tetracycline, erythromycin and moxifloxacin. PCR ribotypes 017 and 002 with multi-drug resistance are rapidly emerging and continuous surveillance is important to monitor the epidemiology of C. difficile to prevent outbreaks of CDI.
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Affiliation(s)
- Viola C Y Chow
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Thomas N Y Kwong
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Erica W M So
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Yolanda I I Ho
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Sunny H Wong
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. .,Institute of Digestive Disease, State Key Laboratory of Digestive Disease, and Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. .,The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
| | - Raymond W M Lai
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Raphael C Y Chan
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
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Peng Z, Liu S, Meng X, Liang W, Xu Z, Tang B, Wang Y, Duan J, Fu C, Wu B, Wu A, Li C. Genome characterization of a novel binary toxin-positive strain of Clostridium difficile and comparison with the epidemic 027 and 078 strains. Gut Pathog 2017; 9:42. [PMID: 28794800 PMCID: PMC5547579 DOI: 10.1186/s13099-017-0191-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 07/25/2017] [Indexed: 12/13/2022] Open
Abstract
Background Clostridium difficile is an anaerobic Gram-positive spore-forming gut pathogen that causes antibiotic-associated diarrhea worldwide. A small number of C. difficile strains express the binary toxin (CDT), which is generally found in C. difficile 027 (ST1) and/or 078 (ST11) in clinic. However, we isolated a binary toxin-positive non-027, non-078 C. difficile LC693 that is associated with severe diarrhea in China. The genotype of this strain was determined as ST201. To understand the pathogenesis-basis of C. difficile ST201, the strain LC693 was chosen for whole genome sequencing, and its genome sequence was analyzed together with the other two ST201 strains VL-0104 and VL-0391 and compared to the epidemic 027/ST1 and 078/ST11 strains. Results The project finally generated an estimated genome size of approximately 4.07 Mbp for strain LC693. Genome size of the three ST201 strains ranged from 4.07 to 4.16 Mb, with an average GC content between 28.5 and 28.9%. Phylogenetic analysis demonstrated that the ST201 strains belonged to clade 3. The ST201 genomes contained more than 40 antibiotic resistance genes and 15 of them were predicted to be associated with vancomycin-resistance. The ST201 strains contained a larger PaLoc with a Tn6218 element inserted than the 027/ST1 and 078/ST11 strains, and encoded a truncated TcdC. In addition, the ST201 strains contained intact binary toxin coding and regulation genes which are highly homologous to the 027/ST1 strain. Genome comparison of the ST201 strains with the epidemic 027 and 078 strain identified 641 genes specific for C. difficile ST201, and a number of them were predicted as fitness and virulence associated genes. The presence of those genes also contributes to the pathogenesis of the ST201 strains. Conclusions In this study, the genomic characterization of three binary toxin-positive C. difficile ST201 strains in clade 3 was discussed and compared to the genomes of the epidemic 027 and the 078 strains. Our analysis identified a number fitness and virulence associated genes/loci in the ST201 genomes that contribute to the pathogenesis of C. difficile ST201. Electronic supplementary material The online version of this article (doi:10.1186/s13099-017-0191-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhong Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Sidi Liu
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Xiujuan Meng
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Wan Liang
- MOE Key Laboratory of Animal Genetics, Breeding, and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Zhuofei Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Biao Tang
- Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang China
| | - Yuanguo Wang
- The Hormel Institute, University of Minnesota, Austin, MN 55912 USA
| | - Juping Duan
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China.,Department of Pharmacy, Changsha Hospital of Traditional Chinese Medicine, Changsha, 410000 Hunan China
| | - Chenchao Fu
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Bin Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Anhua Wu
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Chunhui Li
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
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Shankar J. Insights into study design and statistical analyses in translational microbiome studies. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:249. [PMID: 28706917 DOI: 10.21037/atm.2017.01.13] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Research questions in translational microbiome studies are substantially more complex than their counterparts in basic science. Robust study designs with appropriate statistical analysis frameworks are pivotal to the success of these translational studies. This review considers how study designs can account for heterogeneous phenotypes by adopting representative sampling schemes for recruiting the study population and making careful choices about the control population. Advantages and limitations of 16S profiling and whole-genome sequencing, the two primary techniques for measuring the microbiome, are discussed followed by an overview of bioinformatic processing of high-throughput sequencing data from these measurements. Practical insights into the downstream statistical analyses including data processing and integration, variable transformations, and data exploration are provided. The merits of regularization and ensemble modeling for analyzing microbiome data are discussed along with a recommendation for selecting modeling approaches based on data-driven simulations and objective evaluation. The review builds on several recent discussions of study design issues in microbiome research but with a stronger emphasis on the downstream and often-ignored aspects of statistical analyses that are crucial for bridging the gap between basic science and translation.
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Blatnik JA, Thatiparti TR, Krpata DM, Zuckerman ST, Rosen MJ, von Recum HA. Infection prevention using affinity polymer-coated, synthetic meshes in a pig hernia model. J Surg Res 2017; 219:5-10. [PMID: 29078909 DOI: 10.1016/j.jss.2017.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 04/06/2017] [Accepted: 05/01/2017] [Indexed: 01/17/2023]
Abstract
BACKGROUND Given concern for hernia mesh infection, surgeons often use biologic mesh which may provide reduced risk of infection but at the cost of decreased repair durability. We evaluated mesh coating to provide sustained release of antibiotics to prevent prosthetic mesh infection and also allow a durable repair. MATERIALS AND METHODS Cyclodextrin-based polymer was crosslinked onto multifilament polyester mesh and loaded with vancomycin (1.75 mg/cm2). Pigs received modified meshes (n = 6) or normal, untreated meshes (n = 4), which were implanted into acute 10 × 5 cm ventral hernia, then directly inoculated with 106 colony-forming unit (CFU) of methicillin-resistant Staphylococcus aureus (MRSA). These were compared to animals receiving normal, uninfected mesh. All mesh was secured in an underlay bridge manner, and after 30 d, the abdominal wall was removed for quantitative bacterial culture and biomechanical analysis. RESULTS All animals survived 30 d. All six animals with coated mesh cleared MRSA infection. The four control animals did not clear MRSA (P = 0.005). Quantitative bacterial load was higher in standard mesh versus drug-delivery mesh group (2.34 × 104versus 80.9 CFU/gm). These data were log10-transformed and analyzed by Welch's t-test (P = 0.001). Minimum number of CFUs detectable by assay (300) was used instead of zero. Biomechanical analysis of controls (1.82 N/mm infected; 1.71 N/mm uninfected) showed no difference to the modified meshes (1.31 N/mm) in tissue integration (P = 0.15). CONCLUSIONS We successfully prevented synthetic mesh infection in a pig model using a cyclodextrin-based polymer to locally deliver vancomycin to the hernia repair site and clearing antibiotic-resistant bacteria. Polymer coating did not impact the strength of the hernia repair.
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Affiliation(s)
- Jeffrey A Blatnik
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Thimma R Thatiparti
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - David M Krpata
- Department of Surgery, Cleveland Clinic Comprehensive Hernia Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Sean T Zuckerman
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Michael J Rosen
- Department of Surgery, Cleveland Clinic Comprehensive Hernia Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Horst A von Recum
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio.
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Update on Antimicrobial Resistance in Clostridium difficile: Resistance Mechanisms and Antimicrobial Susceptibility Testing. J Clin Microbiol 2017; 55:1998-2008. [PMID: 28404671 DOI: 10.1128/jcm.02250-16] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Oral antibiotics such as metronidazole, vancomycin and fidaxomicin are therapies of choice for Clostridium difficile infection. Several important mechanisms for C. difficile antibiotic resistance have been described, including the acquisition of antibiotic resistance genes via the transfer of mobile genetic elements, selective pressure in vivo resulting in gene mutations, altered expression of redox-active proteins, iron metabolism, and DNA repair, as well as via biofilm formation. This update summarizes new information published since 2010 on phenotypic and genotypic resistance mechanisms in C. difficile and addresses susceptibility test methods and other strategies to counter antibiotic resistance of C. difficile.
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Wang JZ, Du WT, Xu YL, Cheng SZ, Liu ZJ. Gut microbiome-based medical methodologies for early-stage disease prevention. Microb Pathog 2017; 105:122-130. [DOI: 10.1016/j.micpath.2017.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 02/14/2017] [Accepted: 02/14/2017] [Indexed: 12/17/2022]
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The Oral β-Lactamase SYN-004 (Ribaxamase) Degrades Ceftriaxone Excreted into the Intestine in Phase 2a Clinical Studies. Antimicrob Agents Chemother 2017; 61:AAC.02197-16. [PMID: 28052855 PMCID: PMC5328510 DOI: 10.1128/aac.02197-16] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/20/2016] [Indexed: 12/28/2022] Open
Abstract
SYN-004 (ribaxamase) is a β-lactamase designed to be orally administered concurrently with intravenous β-lactam antibiotics, including most penicillins and cephalosporins. Ribaxamase's anticipated mechanism of action is to degrade excess β-lactam antibiotic that is excreted into the small intestine. This enzymatic inactivation of excreted antibiotic is expected to protect the gut microbiome from disruption and thus prevent undesirable side effects, including secondary infections such as Clostridium difficile infections, as well as other antibiotic-associated diarrheas. In phase 1 clinical studies, ribaxamase was well tolerated compared to a placebo group and displayed negligible systemic absorption. The two phase 2a clinical studies described here were performed to confirm the mechanism of action of ribaxamase, degradation of β-lactam antibiotics in the human intestine, and were therefore conducted in subjects with functioning ileostomies to allow serial sampling of their intestinal chyme. Ribaxamase fully degraded ceftriaxone to below the level of quantitation in the intestines of all subjects in both studies. Coadministration of oral ribaxamase with intravenous ceftriaxone was also well tolerated, and the plasma pharmacokinetics of ceftriaxone were unchanged by ribaxamase administration. Since ribaxamase is formulated as a pH-dependent, delayed-release formulation, the activity of ribaxamase in the presence of the proton pump inhibitor esomeprazole was examined in the second study; coadministration of these drugs did not adversely affect ribaxamase's ability to degrade ceftriaxone excreted into the intestine. These studies have confirmed the in vivo mechanism of action of ribaxamase, degradation of β-lactam antibiotics in the human intestine (registered at ClinicalTrials.gov under NCT02419001 and NCT02473640).
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Involvement of Reduced Microbial Diversity in Inflammatory Bowel Disease. Gastroenterol Res Pract 2016; 2016:6951091. [PMID: 28074093 PMCID: PMC5198157 DOI: 10.1155/2016/6951091] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/19/2016] [Accepted: 11/17/2016] [Indexed: 12/20/2022] Open
Abstract
A considerable number of studies have been conducted to study the microbial profiles in inflammatory conditions. A common phenomenon in inflammatory bowel disease (IBD) is the reduction of the diversity of microbiota, which demonstrates that microbial diversity negatively correlates with disease severity in IBD. Increased microbial diversity is known to occur in disease remission. Species diversity plays an important role in maintaining the stability of the intestinal ecosystem as well as normal ecological function. A reduction in microbial diversity corresponds to a decrease in the stability of the ecosystem and can impair ecological function. Fecal microbiota transplantation (FMT), probiotics, and prebiotics, which aim to modulate the microbiota and restore its normal diversity, have been shown to be clinically efficacious. In this study, we hypothesized that a reduction in microbial diversity could play a role in the development of IBD.
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Detection of a cfr(B) Variant in German Enterococcus faecium Clinical Isolates and the Impact on Linezolid Resistance in Enterococcus spp. PLoS One 2016; 11:e0167042. [PMID: 27893790 PMCID: PMC5125667 DOI: 10.1371/journal.pone.0167042] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/08/2016] [Indexed: 11/24/2022] Open
Abstract
The National Reference Centre for Staphylococci and Enterococci in Germany has received an increasing number of clinical linezolid-resistant E. faecium isolates in recent years. Five isolates harbored a cfr(B) variant gene locus the product of which is capable of conferring linezolid resistance. The cfr(B)-like methyltransferase gene was also detected in Clostridium difficile. Antimicrobial susceptibility was determined for cfr(B)-positive and linezolid-resistant E. faecium isolates and two isogenic C. difficile strains. All strains were subjected to whole genome sequencing and analyzed with respect to mutations in the 23S rDNA, rplC, rplD and rplV genes and integration sites of the cfr(B) variant locus. To evaluate methyltransferase function, the cfr(B) variant of Enterococcus and Clostridium was expressed in both E. coli and Enterococcus spp. Ribosomal target site mutations were detected in E. faecium strains but absent in clostridia. Sequencing revealed 99.9% identity between cfr(B) of Enterococcus and cfr of Clostridium. The methyltransferase gene is encoded by transposon Tn6218 which was present in C. difficile Ox3196, truncated in some E. faecium and absent in C. difficile Ox3206. The latter finding explains the lack of linezolid and chloramphenicol resistance in C. difficile Ox3206 and demonstrates for the first time a direct correlation of elevated linezolid MICs in C. difficile upon cfr acquisition. Tn6218 insertion sites revealed novel target loci for integration, both within the bacterial chromosome and as an integral part of plasmids. Importantly, the very first plasmid-association of a cfr(B) variant was observed. Although we failed to measure cfr(B)-mediated resistance in transformed laboratory strains the occurrence of the multidrug resistance gene cfr on putatively highly mobile and/or extrachromosomal DNA in clinical isolates is worrisome with respect to dissemination of antibiotic resistances.
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Interspecies Interactions between Clostridium difficile and Candida albicans. mSphere 2016; 1:mSphere00187-16. [PMID: 27840850 PMCID: PMC5103046 DOI: 10.1128/msphere.00187-16] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/30/2016] [Indexed: 12/14/2022] Open
Abstract
Candida albicans and Clostridium difficile are two opportunistic pathogens that reside in the human gut. A few studies have focused on the prevalence of C. albicans in C. difficile-infected patients, but none have shown the interaction(s) that these two organisms may or may not have with each other. In this study, we used a wide range of different techniques to better understand this interaction at a macroscopic and microscopic level. We found that in the presence of C. albicans, C. difficile can survive under ambient aerobic conditions, which would otherwise be toxic. We also found that C. difficile affects the hypha formation of C. albicans, most likely through the excretion of p-cresol. This ultimately leads to an inability of C. albicans to form a biofilm. Our study provides new insights into interactions between C. albicans and C. difficile and bears relevance to both fungal and bacterial disease. The facultative anaerobic polymorphic fungus Candida albicans and the strictly anaerobic Gram-positive bacterium Clostridium difficile are two opportunistic pathogens residing in the human gut. While a few studies have focused on the prevalence of C. albicans in C. difficile-infected patients, the nature of the interactions between these two microbes has not been studied thus far. In the current study, both chemical and physical interactions between C. albicans and C. difficile were investigated. In the presence of C. albicans, C. difficile was able to grow under aerobic, normally toxic, conditions. This phenomenon was neither linked to adherence of bacteria to hyphae nor to biofilm formation by C. albicans. Conditioned medium of C. difficile inhibited hyphal growth of C. albicans, which is an important virulence factor of the fungus. In addition, it induced hypha-to-yeast conversion. p-Cresol, a fermentation product of tyrosine produced by C. difficile, also induced morphological effects and was identified as an active component of the conditioned medium. This study shows that in the presence of C. albicans, C. difficile can persist and grow under aerobic conditions. Furthermore, p-cresol, produced by C. difficile, is involved in inhibiting hypha formation of C. albicans, directly affecting the biofilm formation and virulence of C. albicans. This study is the first detailed characterization of the interactions between these two gut pathogens. IMPORTANCECandida albicans and Clostridium difficile are two opportunistic pathogens that reside in the human gut. A few studies have focused on the prevalence of C. albicans in C. difficile-infected patients, but none have shown the interaction(s) that these two organisms may or may not have with each other. In this study, we used a wide range of different techniques to better understand this interaction at a macroscopic and microscopic level. We found that in the presence of C. albicans, C. difficile can survive under ambient aerobic conditions, which would otherwise be toxic. We also found that C. difficile affects the hypha formation of C. albicans, most likely through the excretion of p-cresol. This ultimately leads to an inability of C. albicans to form a biofilm. Our study provides new insights into interactions between C. albicans and C. difficile and bears relevance to both fungal and bacterial disease.
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Sugar and Spice Make Bacteria Not Nice: Protein Glycosylation and Its Influence in Pathogenesis. J Mol Biol 2016; 428:3206-3220. [DOI: 10.1016/j.jmb.2016.04.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/04/2016] [Accepted: 04/08/2016] [Indexed: 01/08/2023]
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Di Pilato V, Freschi G, Ringressi MN, Pallecchi L, Rossolini GM, Bechi P. The esophageal microbiota in health and disease. Ann N Y Acad Sci 2016; 1381:21-33. [PMID: 27415419 DOI: 10.1111/nyas.13127] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/09/2016] [Accepted: 05/12/2016] [Indexed: 12/17/2022]
Abstract
The esophageal mucosa is among the sites colonized by human microbiota, the complex microbial ecosystem that colonizes various body surfaces and is increasingly recognized to play roles in several physiological and pathological processes. Our understanding of the composition of the esophageal microbiota in health and disease is challenged by the need for invasive sampling procedures and by the dynamic nature of the esophageal environment and remains limited in comparison with the information available for other body sites. Members of the genus Streptococcus appear to be the major components of the microbiota of the healthy esophagus, although the presence of several other taxa has also been reported. Dysbiosis, consisting of enrichment in some Gram-negative taxa (including Veillonella, Prevotella, Haemophilus, Neisseria, Campylobacter, and Fusobacterium), has been reported in association with gastroesophageal reflux disease and is hypothesized to contribute to the evolution of this condition toward Barrett's esophagus (which is the most common esophageal precancerous lesion) and, eventually, adenocarcinoma. Some Campylobacter species (mostly C. concisus) are also putatively involved in the progression of disease toward adenocarcinoma. However, variable findings have recently been reported in additional studies. Causative relationships between dysbiosis or specific bacterial species and esophageal diseases remain controversial and warrant further investigations.
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Affiliation(s)
- Vincenzo Di Pilato
- Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
| | - Giancarlo Freschi
- Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.,Gastrointestinal Surgery Unit, Florence Careggi University Hospital, Florence, Italy
| | - Maria Novella Ringressi
- Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.,Gastrointestinal Surgery Unit, Florence Careggi University Hospital, Florence, Italy
| | - Lucia Pallecchi
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Gian Maria Rossolini
- Department of Medical Biotechnologies, University of Siena, Siena, Italy.,Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Microbiology and Virology Unit, Florence Careggi University Hospital, Florence, Italy.,Don Carlo Gnocchi Foundation, Florence, Italy
| | - Paolo Bechi
- Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.,Gastrointestinal Surgery Unit, Florence Careggi University Hospital, Florence, Italy
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Zellmer C, De Wolfe TJ, Van Hoof S, Blakney R, Safdar N. Patient Perspectives on Fecal Microbiota Transplantation for Clostridium Difficile Infection. Infect Dis Ther 2016; 5:155-64. [PMID: 27048199 PMCID: PMC4929085 DOI: 10.1007/s40121-016-0106-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Clostridium difficile infection (CDI) is a severe and increasingly frequent healthcare-associated infection that develops after disruption of the gut microbiota. Immunocompromised, hospitalized patients have an increased likelihood of acquiring CDI, leading to lengthened hospital stays, increased medical fees, and higher rates of morbidity and mortality. Treatment of CDI is challenging because of limited treatment options and a 19-20% recurrence rate. Thus, there is a need for effective, affordable and safe treatments for CDI. Fecal microbiota transplantation (FMT) is the transplantation of donor stool into the intestine of a CDI patient to restore the structure and function of the gut microbiota and eradicate CDI. Recently, FMT has become an attractive alternative treatment for CDI due to its overwhelming success rate. However, the patient perspective on the effect of CDI and the role of FMT in that context is lacking. METHODS We undertook a patient survey to gather qualitative and quantitative data on the short-term social, physical, emotional outcomes for patients with CDI who have undergone FMT. RESULTS We found in all patients interviewed that the social implications of CDI were generally more severe than the emotional and physical aspects. CONCLUSION Future studies should consider evaluating these important patient-centered factors as outcomes. Moreover, patients are willing to undergo FMT as treatment for CDI.
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Affiliation(s)
- Caroline Zellmer
- William S. Middleton Veterans Hospital, Madison, WI, USA.
- Section of Infectious Diseases, Department of Medicine, University of Wisconsin, Madison, WI, USA.
| | - Travis J De Wolfe
- William S. Middleton Veterans Hospital, Madison, WI, USA
- Section of Infectious Diseases, Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Sarah Van Hoof
- William S. Middleton Veterans Hospital, Madison, WI, USA
- Section of Infectious Diseases, Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Rebekah Blakney
- William S. Middleton Veterans Hospital, Madison, WI, USA
- Section of Infectious Diseases, Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Nasia Safdar
- William S. Middleton Veterans Hospital, Madison, WI, USA
- Section of Infectious Diseases, Department of Medicine, University of Wisconsin, Madison, WI, USA
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